There are many similarities of the two poems. Each poem has six stanzas that have four lines each. The use of the four-line stanza directly illustrates the deep desire of the shepherd to his love by repetitiously calling to the one he loves. As in the Nymph's reply her continual denial to the shepherd is continually and strongly stressed in each of the six stanzas.
The form also allows the poem to flow freely without any interruption. Having no interruption enables, one who reads these poems, to see a visual image and to hear the desperation of both the characters trying desperately to get their point across. When a poem is able to flow freely one can also be able to understand the poem better and take in a deeper meaning of the poem unlike a poem all jumbled up and confusing.
There also are some differences in the two poems. The first difference is what the character is trying to get across to the reader. In "The Passionate Shepherd to His Love" the shepherd is able, and willing, to provide anything and everything no matter what the cost to his love. As we see in the Nymph's reply, she obviously has a grip on reality and knows that the shepherd's promises can not possibly come true. Flowers will die. Rivers will rage. Winter dose come.